1. Field of the Invention
The present invention relates to the field of portable electronic devices, such as personal digital assistants or handheld computer systems. Specifically, the present invention relates to a protective transparent cover allowing access to an interface mechanism for navigating among applications with the protective cover in place.
2. Related Art
A portable computer system, such as a personal digital assistant (PDA) or handheld computer, is an electronic device that is small enough to be held in the hand of a user. By virtue of their size, portable computer systems are lightweight and so are exceptionally portable and convenient. Portable computer systems are rapidly becoming smaller and at the same time, increasing functionality and user friendliness.
These systems, and others like them, have in common some type of screen for displaying images as part of a user interface. Many different kinds of screens can be used, such as liquid crystal displays, field emission displays or other types of flat screen displays. Many have keyboards that can be displayed on a touch screen and selected with a stylus. Many have the capability of reading handwritten memos. Recently, complete keyboards have been incorporated in the form of small depressible buttons on the housing of the devices.
These systems also have in common some type of user interface allowing a user to input commands and information and to navigate either within an application or from one application to another. Handheld computers and many other handheld devices typically have multiple built-in, dedicated or programmable buttons or keys that can be used to implement various functions and to navigate among and within different applications. Some also have a one-touch navigation assembly that allows scrolling in four directions and making a selection from a single central location on the housing.
In order to protect these pocket-sized devices from being inadvertently activated while in a pocket, briefcase, purse or other transport facility, many of these devices have protective covers that cover the buttons. FIGS. 1A and 1B illustrate two embodiments of covers found in the prior art. FIG. 1A illustrates a rigid flip cover that snaps onto a PDA device at the back of the device and is lifted to provide access to the buttons and display screen. A flip cover needs a solid connection to the device, which then becomes difficult to remove when so desired. When the cover is in place, the device cannot be used. Once lifted, the cover can prove to be unwieldy when attempting to hold the PDA while using it.
FIG. 1B illustrates another example of covers found on handheld computer devices in the prior art. In this example, the cover is in the form of a rigid notebook style cover that has a flexible frame on one side into which the device may be slipped. The frame fits around the perimeter of the device and below the navigation buttons and has a strip that fits above the navigation buttons but below the screen to further secure the device in the cover. This cover, as with the cover of FIG. 1A, proves uncomfortable for holding while navigating or executing applications. The device is best used, while in the cover, when placed on a flat surface. In neither of the embodiments shown in FIGS. 1A and 1B does the cover lend itself to comfortably navigating with one hand, and in both embodiments the cover must be lifted or removed in order to access the navigation buttons. There are a number of types of covers available in the prior art, but they either do rot allow for easy release, or they do not allow for use of the handheld device while in place.
Referring to Prior Art FIG. 2A, an exemplary handheld electronic computing device 200a is illustrated, according to one embodiment of the prior art. Device 200a is configured for single-handed navigation utilizing a ring and button assembly. In the present embodiment, navigation ring 210 and button 215 are located at the lower portion of the face of device 200a and the ring 210 may be pressed at positions corresponding to twelve o'clock, three o'clock, six o'clock and nine o'clock to cause a highlighting feature to move up, right, down and left, respectively, among icons on display screen 220. The highlighted icon may be selected by pressing button 215.
The ring and button assembly has the advantage of performing multiple functions using one hand within a concentrated area. The present assembly is relatively large and occupies a considerable amount of space on housing 225 of FIG. 2A. Some newer handheld devices are incorporating additional function buttons and even complete keyboards. With the ever-increasing need for smaller form factors and additional function keys, it would be desirable to have a navigation ring and button assembly that is smaller in size than the current design.
Prior Art FIG. 2B illustrates actuator devices 200b used in one embodiment of the prior art. Actuators 230, 240, 250, 260 and 270 are small, depressible steel domes placed in a matrix with circuitry below for communicating with the handheld device. The ring 210 of FIG. 2A would fit over outer four domes 230, 240, 250 and 260 and button 215 of FIG. 2A would fit above center dome 270. In order to achieve up, down, right and left movement and a select function, 5 domes are used. The dome can be cycled (e.g., pressed and released) only a limited number of times during its lifetime. The larger the dome, the greater the number of cycles in a lifetime. Thus, to maintain reliability, it would not be desirable to reduce the size of the domes to fit a smaller space. The spacing between the domes allows the sides of the ring and button to have sufficient clearance for movement.
In summary, prior art mechanisms for protecting hand-held devices are problematic. A solution to the problems described above would be advantageous. The present invention, in various embodiments, provides such a solution.